Curmudgeon wrote:
On 1/27/2015 4:52 PM, Pico Rico wrote:
A friend has a house in the mountains. No A.C. The furnace is as old as
the house, probably 1965 or 1970. Are new furnaces more efficient in
their
use of natural gas, and thus "pay for themselves"? If so, how does one
calculate the anticipated savings and pay back period?



If your fuel bill is $1000/yr, an 80% efficient furnace would use $800
to heat your house and $200 would go out the exhaust.

If you bought a 98% efficient furnace, your fuel bill for the house
would drop to $816, $800 to heat your house and $16 up the chimney.

FWIW, don't count on saving any money over the life of the furnace
though. High-efficiency furnaces break down a lot as they age.
Any fuel savings you accrue today will be eaten up with expensive
repairs after the furnace is 10 years old or so.

A co-worker paid $260 to have a safety switch replaced on her high
efficiency furnace last season. This year was another $610 for a draft
inducer.
In my opinion, high efficiency furnaces are poorly engineered junk.


Hi,
IMO. this is too simplistic over statement. Of course old furnaces do
not have inducer motor, but has safety switch. Maybe your coworker was
not replacing filter regularly causing over heat.